JP2590835Y2 - Pipe fittings - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting a synthetic resin pipe (hereinafter referred to as "resin pipe"), and in particular, has a commonality with a pipe joint for connecting a synthetic resin-coated steel pipe (hereinafter referred to as "resin-coated steel pipe"). For improvement.

[0002]

2. Description of the Related Art Conventionally, as a pipe joint for connecting a resin-coated steel pipe, there is one shown in FIG. 3 disclosed in Japanese Utility Model Application Laid-Open No. 64-45080. Since this type of pipe joint is used for underground conduits, an anticorrosion layer is formed on the outer surface. That is, the joint body 2 has the resin coating layer 1 on the outer surface, and the pressing ring 4 also has the resin coating layer 3 on the outer surface, and these are connected by screwing. Further, a pipe fastening mechanism similar to the conventional one is provided inside, which comprises a retainer 6 and a packing 5.
And a biting ring 7 having biting projections at intervals on the circumference and a tapered portion 11 formed inside the pressing ring. Therefore, when the press ring is screwed to the joint body, the packing 5 is compressed to exhibit airtightness, and the biting ring 7 is pressed toward the center of the pipe, thereby achieving the pull-out preventing force of the pipe. Further, in order to prevent invasion of water and foreign matter from the outside, the inside of the annular resin case 16 having a U-shaped cross section so as to flexibly cope with scratches on the resin-coated portion 19 of the connected pipe and variations in the outer diameter. Sealing member filled with butyl rubber 17
It has been proposed to provide the opening 15 at the end of the pressing wheel. According to this, the butyl rubber 17 in the case 16 is pushed out together with the connection of the pressing ring 4, and the butyl rubber is filled over the entire circumference between the outer surface of the tube and the inner surface of the pressing ring, thereby achieving waterproofing.

On the other hand, pipe joints for connecting resin pipes include:
FIG. 4 disclosed in Japanese Utility Model Application Laid-Open No. 62-20286 is shown. In the figure, a pipe joint for a resin-coated steel pipe is shown on the left side, and a structure basically similar to the above-described pipe joint is disclosed, although the threading of the threaded portion is different. And the pipe joint for resin pipes is shown on the right side. As can be seen from this figure, the structure of the joint body and the press ring is of course the same in this pipe joint, and the pipe fastening mechanism relating to the airtight structure and pull-out prevention is basically the same as that for the coated steel pipe. However, resin pipe 20 is coated steel pipe 18
The difference is that the shape and the material of the bite ring are different, and the outer diameter of the resin tube is smaller than that of the resin tube. From the above, it can be considered that the joints for resin-coated steel pipes and the joints for resin pipes can be shared by replacing the parts of the fastening mechanism that have been used conventionally with the other joint body and pressing ring. It can be measured. This is beneficial for both the manufacturer and the user in terms of manufacturing, parts management, and cost.

[0004]

In view of this common use, there is no problem because the parts of the fastening mechanism are produced in large quantities compared to the past, but if the above-mentioned seal member is also used in common, the resin pipe will not be used. However, since the diameter of the tube becomes small, the filling amount of butyl rubber is insufficient, and even if butyl rubber pops out, it does not reach the entire circumference of the end portion of the pressing wheel, and thus the waterproof effect is not perfect. Therefore, it was not possible to use common parts for the sealing member. SUMMARY OF THE INVENTION An object of the present invention is to provide a pipe joint which can solve the above-mentioned problem and can share parts of a sealing member between a resin-coated steel pipe and a resin pipe by simply adding a simple part.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a pipe joint for connecting a synthetic resin-coated steel pipe or a synthetic resin pipe, wherein a joint body having a resin coating layer on an outer surface is screwed to an end of the joint body. And a push ring having a resin coating layer on the outer surface, a retainer is interposed inside the connection between the joint body and the push ring, a packing is disposed on the joint body side with the retainer interposed therebetween, and And a taper portion for pressing the bite ring in the pipe center direction by screw connection with a joint body is formed inside the pressing ring, and a cross section is formed between the bite ring and the tapered portion inner surface. When connecting a synthetic resin pipe to a pipe joint in which a sealing member filled with butyl rubber in a U-shaped annular resin case is installed with the open side of the case facing the end of the press ring, the synthetic resin pipe is connected. In approximately L-shaped cross section between the outer and the sealing member of the fat pipe, a pipe joint which is interposed an annular member having a thickness such as to be substantially equal to the outer diameter of the resin-coated steel pipe.

[0006]

The annular member is interposed between the sealing member and the synthetic resin, and has substantially the same outer diameter as that of the coated steel pipe. Even if the sealing member for the coated steel pipe is commonly used, the filling amount of butyl rubber can be reduced. The amount of protrusion is also appropriate, and the waterproof effect of this portion is perfect. Therefore, the sealing member can be shared by simply adding this simple annular member.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In the drawings of the embodiments, the same components as those in the conventional drawings shown in FIGS. 3 and 4 are denoted by the same reference numerals.
FIG. 1 shows a partial cross-sectional view after connecting a resin pipe 20 (polyethylene pipe). The pipe joint has an internal thread on its inner surface.
Although there is no change in having a joint body 2 having a resin coating layer 1 on the outer periphery, a pressing ring 4 also having a screw and a resin coating layer 3 on the outer surface, a packing 5, a retainer 6, and a biting ring 7, there is no difference. The end and the inner surface on the side of the end are covered with the resin coating layer 3, and the inner surface of the coating layer 3 is formed as a tapered inner surface that expands toward the end. The biting ring 10 is formed of a hard plastic ring having a circular cutout on the circumference and having a saw-toothed biting projection on the inner peripheral side. A protrusion is formed on the outer surface of the resin coating layer of the pressing wheel 4.
A rubber ring 14 having an inverted Y-shaped cross section fitted to the projection 31 is attached, and is circumferentially in contact with the inner surface of the resin coating layer 1 extending to the end on the joint body 2 side to be in contact with the joint body 2. The outer surface of the pressing wheel 4 is sealed. And the tapered portion of the inner surface of the pressing wheel 4
A sealing material 15 filled with flexible butyl rubber 17 in an annular thin resin case 16 having a U-shaped cross section is mounted between the biting ring 10 and 11. The sealing material 15 is mounted with the open side of the U-shaped section of the case facing the end of the pressing wheel 4. In this mounting, an annular member 13 made of plastic and having an L-shaped cross section is mounted on the outer surface of the resin tube and interposed therebetween. For example, in this case, the resin pipe has a diameter of about 3 mm smaller than the resin-coated steel pipe, and thus has an L-shape having a thickness of about 1.5 mm. Then, the outer surface of the resin coating layer 3 of the pressing wheel 4 is tightened with a wrench or the like, so that the case 16
Is compressed by the tapered portion 11 of the pressing ring and the L-shaped portion of the annular member 13, and the butyl rubber 17 in the case 16 is pushed out toward the inner end of the pressing ring, and the outer surface of the resin tube 20 and the resin coating layer of the pressing ring 4 are formed. 3. Seal and fill.

Next, another embodiment of the present invention is shown in FIG. This example is a pipe joint for connecting a relatively small-diameter (50 A or less) polyethylene pipe 20. In contrast to the one shown in FIG. Other mechanisms are the same except that the screw is reversed. Therefore, although detailed description is omitted, the annular member 13 having a substantially L-shaped cross section is used.
Is the same as using. As described above, when connecting a resin pipe having an outer diameter smaller than that of the resin-coated steel pipe, an annular member having a substantially L-shaped cross section having a thickness to compensate for the small diameter is used. And the amount of the seal member is optimized, and a common sealing member is achieved.
In addition, the presence of the annular member facilitates centering of the resin tube with respect to the center of the joint, and overall facilitates operations such as tightening of the press ring. Further, since butyl rubber does not flow into the biting ring side, the tightening force of the pressing ring is constant and stable.

According to the present invention, in a pipe joint for connecting a resin-coated steel pipe or a resin pipe, parts can be shared for a conventional sealing member.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a pipe joint showing one embodiment of the present invention.

FIG. 2 is a partial sectional view of a pipe joint according to another embodiment.

FIG. 3 is a partial cross-sectional view of a conventional pipe joint for a resin-coated steel pipe.

FIG. 4 is a partial cross-sectional view of a conventional pipe joint for a resin pipe.

[Explanation of symbols]

 1,3 ... resin coating layer 2 ... joint body 4 ... press ring 5, 8 ... packing 6, 9 ... retainer 7, 10 ... bite ring 13 ... annular member 15 ... seal member 18 ... resin-coated steel pipe 20 ... resin pipe

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16L 17/00-19/08 F16L 21/00-21/08

Claims (1)

(57) [Scope of request for utility model registration] 1. A pipe joint for connecting a synthetic resin-coated steel pipe or a synthetic resin pipe, wherein a joint body having a resin coating layer on an outer surface is connected by screwing to an end of the joint body, and the outer surface is coated with a resin. A push ring having a layer, a retainer is interposed inside the connection between the joint body and the push ring, a packing is arranged on the joint body side across the retainer, and a bite ring having a bite projection is arranged on the push ring side. A tapered portion for pressing the biting ring toward the pipe center is formed inside the pressing wheel by screw connection with the joint body, and a U-shaped cross section is formed between the biting ring and the inner surface of the tapered portion. When a synthetic resin pipe is connected to a pipe joint in which a sealing member filled with butyl rubber is provided with the open side of the case facing the end of the press ring, an outer surface of the synthetic resin pipe and the seal section are connected. A pipe joint characterized in that an annular member having a substantially L-shaped cross section and a thickness substantially equal to the outer diameter of the resin-coated steel pipe is interposed between the pipe and the material.